“We finally know the parentage of the largest known dinosaur eggs,” Dr. Zelenitsky said. The findings were published Tuesday in the journal Nature Communications.
These kinds of large dinosaur eggs are known as Macroelongatoolithus eggs, and have also been found in North America. They are typically arranged in a large ring with up to about 30 eggs in a nest. But only the clutch with Baby Louie offered a skeleton that was closely associated with the eggs. It provided the best clues for figuring out what creatures could produce such massive eggs.
Entombed in a large block of rocks, Baby Louie was collected sometime between December 1992 and early 1993 in China. Charlie Magovern, a fossil dealer, came into possession of the rocks and unexpectedly discovered the fossilized fetus bones. In 1996, Baby Louie was featured on the cover of National Geographic, and was named after the photographer for the feature article, Louie Psihoyos.
Baby Louie remained with the fossil dealers until 2001, when they sold it to the Indianapolis Children’s Museum. The museum put the fossil on display for about 12 years. During this time an exciting discovery occurred in China: The first giant oviraptorosaur fossil was unearthed in 2007.
Paleontologists had previously known of oviraptors, and they were aware that Baby Louie resembled one. But until that time, all of the oviraptors that had ever been found were much too small to have laid the giant eggs. But with the newly discovered one-ton oviraptorosaur, the idea that the massive eggs came from a giant oviraptorosaur seemed plausible.
“Finally here it is — there are giant oviraptorosaurs that could have laid these eggs,” Dr. Zelenitsky said.
Still, even with the discovery of giant oviraptorosaurs, it took another decade before the researchers could publish the connection. Concerned about the legal status of the fossil, Dr. Zelenitsky and her colleagues wanted to wait until Baby Louie was repatriated to China. In 2013, the fossilized embryo was finally returned and put on display in the Henan Geological Museum in Zhengzhou. Then in 2015, some of Dr. Zelenitsky’s colleagues returned to the site in China where Baby Louie was found and uncovered fossilized egg shells that were identical to the ones from “Baby Louie’s nest.
David J. Varricchio, a paleontologist from Montana State University, who was not involved in the study, said it was satisfying to finally see the identity of Baby Louie confirmed. He added that the findings could help paleontologists better understand dinosaurs and their eggs.
“It answers an interesting puzzle of who these giant eggs belong to,” he said.